ethernet stopped working

Hi, Yesterday my ethernet just stopped working. I was hooked up to my cable modem and it stopped working. I checking in my device manager and it does not even show it any more.
I have an Acer Aspire Model 5740 Lap Top Intel I5
Windows 7 Ultimate
I went onto Acer support and made sure my chipset and bios were up to date.
I have tried a different ethernet cable but not luck.
I can hook up my ethernet to my Linksys router and go wireless with no problem.
I do not know what else to check to force my computer to recognise the ethernet port. Or could it just have died?
If so is there such a thing as an external ethernet hookup I can get and install?
Thanks for any and all help in advance.

 

In Device Manager, Right click Network Adapters and select Scan for hardware changes. Windows might detect it missing and install the driver. Or try reinstalling the driver. You can purchase a USB to Ethernet adapter like this. It is one of the few that will support Windows 7.

Here is another from newegg that will support Windows 7.

http://www.newegg.com/Product/Product.aspx?Item=N82E16833327018